Production of nanoparticle added polymeric sensors and determination of sensitivity to volatile organic compounds

Volatile organic compounds (VOCs) are recognized as critical pollutants that pose serious threats to both environmental quality and human health. Even at trace concentrations, compounds such as methanol, ethanol, acetone, toluene, xylene, chloromethane, hydrazine, and dimethylformamide can induce acute and chronic exposure effects, leading to significant health risks. Therefore, continuous monitoring of these compounds within safe limits is essential. Gas sensors have been widely utilized for environmental monitoring due to their high sensitivity and selectivity. Among the available sensing materials, polymer-based thin films have gained considerable attention owing to their high surface-to-volume ratios, low production costs, and structural flexibility. The solvent casting technique, which allows the fabrication of uniform and stable thin films in a simple and cost-effective manner, is commonly employed in their preparation. However, to enhance sensing efficiency, these films require functional modification with conductive or semiconductive additives. Nanoparticles, particularly metal oxides, have been shown to significantly improve the gas-sensing performance of polymer matrices. In this study, thin films were fabricated from polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) via the solvent casting method and subsequently functionalized with silver, titanium dioxide, and iron nanoparticles. Nanocomposite films were prepared in various combinations, and their physicochemical and morphological properties were systematically characterized. Finally, their sensitivities toward selected VOCs were evaluated. The findings of this thesis indicate that nanoparticle-modified polymer thin films demonstrate strong potential as efficient sensor materials for the detection of volatile organic compounds.